                                      :sem {:aspect :progressive
                                            :tense :past}}})
 
-                   (unifyc c10
+                   (unify-check c10
                            root-is-head-root
                            {:rule "s-present-phrasal-head"
                             :head {:phrasal true}

                                     :cat :verb
                                     :sem {:aspect :progressive
                                           :tense :present}}})
                   (unifyc c10
                           root-is-head
                           {:rule "s-present-nonphrasal-head"
                            :head {:phrasal false}


(defn modal-is-head-feature [phrase]
  (cond (= :verb (get-in phrase '(:synsem :cat)))
        (unify-check phrase
                (let [ref (atom :top)]
                  {:synsem {:modal ref}
                   :head {:synsem {:modal ref}}}))
